If the presentation display was changed, the taskbar may have moved off of the visible screen:

• Press [Windows logo key + P] key to bring up the presentation display mode options
• Make sure Computer Only or Extended is selected
• Use the arrow keys to toggle between options and Enter to select the correct display mode

The taskbar may be set to “Auto-hide”:

• Press the Windows key on the keyboard to bring up the Start Menu
• Right-Click on the taskbar and select Taskbar settings
• Toggle the Automatically hide the taskbar in desktop mode switch and click Apply
• If it is now checked, move the cursor to the bottom, right, left, or top of the screen and the taskbar should re-appear
• Repeat step three to return to your original setting

The Explorer may have crashed:

• Open the Task Manager using either [Ctrl+Alt+Del] or [Ctrl+Shift+Esc]
• If explorer.exe is already running, select it and choose End Task before continuing on
• Click the File menu and select New Task
• In the dialog box, type explorer.exe to restart the process